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Tax filing deadlines — St. Gallen 2026

When it's due, how to extend it, and what happens if you don't.

Base filing deadline

31 MarchVerified

In St. Gallen, extension requests go through your commune's tax office, not a central cantonal portal — process and fee practice can vary from one commune to the next.

Extension

A request is required.

Request through your commune's tax office (Gemeindesteueramt), not a cantonal portalOnline or written request to the Gemeinde

  • FreeNot confirmed
Not published. No official source states a hard maximum date for this canton.Not confirmed
Contact your commune's tax office

If you miss it

  • CHF 250Verified

The one deadline that's the same everywhere

A Pillar 3a contribution or pension-fund (BVG) buy-in counts for a tax year only if it's credited to your account by 31 December of that year — the date you initiate the payment doesn't count, only the date it lands.

Banks and 3a foundations often close their own booking cutoff a few days early (commonly ~24–27 December) so the payment posts in time — that's provider practice, not law, so don't wait until the 31st.

Sources & methodology
When is the St. Gallen tax return due?
31 March for employees / standard filers.
Can I get a deadline extension in St. Gallen?
Yes — see the Extension section above for the exact process, cost, and channel.
What happens if I miss the deadline in St. Gallen?
See the "If you miss it" section above for this canton's specific consequences.
When's the deadline for a Pillar 3a contribution?
31 December, nationwide, for every canton — and the payment must be credited to your account by then, not just sent.

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